The LTE (Long-Term Evolution) has been known as one standard of a wireless cellular system. A mechanism regarding a communication failure, occurring in wireless communication terminals (or terminals) in the LTE system, will be described below (see Non-Patent Literature Documents 1, 2).
The outline of procedures performed with wireless communication terminals upon detecting radio link failures (RLF: Radio Link Failure) will be described below.
FIG. 11 is an illustration showing an example of a procedure performed with a wireless communication terminal upon detecting a radio link failure in the LTE system. All the processes will be carried out in a wireless communication terminal.
When a wireless communication terminal undergoes a communication failure, it detects RLF at first (step S1001).
Upon detecting RLF, a wireless communication terminal starts a radio link reconfiguration procedure (RRC Reconfiguration Procedure). The wireless communication terminal restarts communication with a connected station upon normally completing the reconfiguration procedure.
When a wireless communication terminal fails to perform a reconfiguration procedure (step S1002), it starts a process to select a reconnected base station (Cell Reselection). When the wireless communication terminal is successfully connected to the originally connected station owing to the cell reselection, it may receive data from its intermediate part during transmission.
However, all the data retained in a base station during a transmission standby state will be lost when the reconnected base station of a wireless communication terminal differs from the original base station (i.e. when a wireless communication terminal selects another base station, other than the currently connected base station, as the reconnected base station). In this case, the wireless communication station should carry out data transmission/reception from the beginning, which in turn may cause a significant communication delay in the wireless communication terminal.
Additionally, a communication failure may occur when a wireless communication terminal fails to discover an appropriate base station as the reconnected base station.
As an example of a prior art, Patent Literature Document 1 discloses a wireless communication terminal which is able to continue an interterminal communication without the need of an operation of registering identification and key information in advance even when it moves outside of wireless communication range during communication.